Brewer Research Articles

Genome-Wide Identification and Preliminary Functional Analysis of BAM (β-Amylase) Gene Family in Upland Cotton.

The β-amylase (BAM) gene family encodes important enzymes that catalyze the conversion of starch to maltose in various biological processes of plants and play essential roles in regulating the growth and development of multiple plants. So far, BAMs have been extensively studied in Arabidopsis thaliana (A. thaliana). However, the characteristics of the BAM gene family in the crucial economic crop, cotton, have not been reported. In this study, 27 GhBAM genes in the genome of Gossypium hirsutum L (G. hirsutum) were identified by genome-wide identification, and they were divided into three groups according to sequence similarity and phylogenetic relationship. The gene structure, chromosome distribution, and collinearity of all GhBAM genes identified in the genome of G. hirsutum were analyzed. Further sequence alignment of the core domain of glucosyl hydrolase showed that all GhBAM family genes had the glycosyl hydrolase family 14 domain. We identified the BAM gene GhBAM7 and preliminarily investigated its function by transcriptional sequencing analysis, qRT-PCR, and subcellular localization. These results suggested that the GhBAM7 gene may influence fiber strength during fiber development. This systematic analysis provides new insight into the transcriptional characteristics of BAM genes in G. hirsutum. It may lay the foundation for further study of the function of these genes.

Interesting Behavior of Geranic Acid during the Beer Brewing Process: Why Could Geranic Acid Remain at a Higher Level Only in the Beer Using Sorachi Ace Hops?

Hops are among the most important ingredients in beer that contribute to beer flavor. Consequently, novel types of hops have been bred and widely used worldwide. For example, the Sorachi Ace hop imparts characteristic varietal aromas, including woody, pine-like, citrus, dill-like, and lemongrass-like aromas, to the finished beer. In our previous study, the unique volatile compound geranic acid was significantly detected only in the test beer brewed with the Sorachi Ace hop; moreover, the coexistence of geranic acid and other hop-derived flavor compounds could result in the characteristic aroma of the Sorachi Ace beers. In this study, selected hop-derived flavor compounds, including geranic acid, were compared among 17 hop varieties. The geranic acid content in the Sorachi Ace hop was the highest among the studied hops. We also investigated the behavior of geranic acid and related flavor compounds throughout the fermentation process. The content of geranic acid was higher than those of the other compounds during fermentation. Next, we compared the concentrations of these compounds in kettle-, late-, and dry-hopped beers using Sorachi Ace hop. The results revealed that geranic acid remained at higher concentrations from the worts to finished beers despite the decrease in the content of other hop-derived flavor compounds as a result of evaporation and/or other factors during brewing. Further, geranic acid could remain at high levels in the test-brewed beers with Sorachi Ace hops because of its behavior as an acid throughout the brewing process, including during wort boiling and fermentation.

Effects of crushing and enzyme treatment on physicochemical, fermentation performance, and antioxidant properties of qingke (hull-less barley) wort

Crushing and enzyme treatment are pivotal factors that cannot be ignored in the mashing stage of qingke (hull-less barley) craft beer brewing. This study aimed to explore the impact of different mashing conditions on physicochemical, fermentation, and antioxidant properties of qingke wort as well as elucidate the mechanisms of mashing conditions affecting the quality of qingke wort. The results showed that wort with a high fermentable sugar content, including maltose and glucose, could be obtained using a crushed size smaller than 0.9 mm. Furthermore, enzyme treatment further led to an increase in fermentable sugar content, enhancing the fermentation capacity of qingke wort. Notably, crushing significantly affected the antioxidant properties of qingke wort, with smaller crushed particle sizes yielded superior antioxidant properties to the wort, mainly due to the increase in the content of phenolic compounds such as chlorogenic acid, caffeic acid, and epicatechin.

Optimizing brewing beer production using Aspergillus oryzae solid-state fermentation of sorghum koji as an adjunct

ABSTRACT This study employed solid-state fermentation (SSF) to substitute 30% barley malt with Kinmen waxy sorghum and Australian non-waxy sorghum inoculated with Aspergillus oryzae for koji preparation in the production of sorghum beer. Optimal conditions for koji preparation were determined, and various beer formulations were developed based on Kinmen sorghum koji. The optimal soaking time for Kinmen waxy and Australian non-waxy sorghum was 2.5 h at room temperature with a water absorption rate of 35%. After steaming, Kinmen sorghum and Australian sorghum exhibited blowup rates of 75.33% and 85.67%, respectively. Five beer types were fermented for 12 days using different mashing methods. Glucose content ranged from 9.93 to 17.6 g/L on the first day, decreasing to 0.03 g/L by the third day. On the 12th day, the alcohol content peaked at 3.03–4.39%, with a pH range of 4.3–5.7. Aroma analysis identified higher alcohols, such as ethanol, 3-methyl-1-butanol, and 2-phenyl ethanol, as the main contributors, with 2-phenyl ethanol imparting a solid rose flavor and ethanol providing a hop aroma and mild taste. Given the global competitiveness of the beer industry, our research emphasizes the use of Kinmen sorghum-based malt, offering unique flavors and a rich aroma, presenting significant growth potential in the market.

Fermentation-mediated variations in structure and biological activity of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg

Variations in the structure and activities of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg fermented by Sanghuangporus sanghuang fungi were investigated. Compare with the unfermented polysaccharide (THDP2), the major monosaccharide composition and molecular weight of polysaccharide after fermentation (F-THDP2) altered dramatically, which caused galactose-induced conversion from glucose and one-third of molecular weight. F-THDP2 had a molecular weight of 1.23 × 104 Da. Moreover, the glycosidic linkage of F-THDP2 varied significantly, a 1, 2-linked α-d-Galp and 1, 2-linked α-d-Manp backbone was established in F-THDP2, which differed from that of 1, 4-linked α-d-Glcp and 1, 4-linked β-d-Galp in THDP2. In addition, F-THDP2 showed a more flexible chain conformation than that of THDP2 in aqueous solution. Strikingly, F-THDP2 exhibited superior inhibitory effects on HeLa cells via Fas/FasL-mediated Caspase-3 signaling pathways than that of the original polysaccharide. These variations in both structure and biological activities indicated that fermentation-mediated modification by Sanghuangporus sanghuang might a promising novel method for the effective conversion of starch and other polysaccharides from Tetrastigma hemsleyanum Diels et Gilg into highly bioactive biomacromolecules, which could be developed as a potential technology for use in the food industry.

Proteomics and Metabolomics Reveal that an Abundant α-Glucosidase Drives Sorghum Fermentability for Beer Brewing.

Sorghum (Sorghum bicolor), a grass native to Africa, is a popular alternative to barley for brewing beer. The importance of sorghum to beer brewing is increasing because it is a naturally gluten-free cereal, and climate change is expected to cause a reduction in the production of barley over the coming decades. However, there are challenges associated with the use of sorghum instead of barley in beer brewing. Here, we used proteomics and metabolomics to gain insights into the sorghum brewing process to advise processes for efficient beer production from sorghum. We found that during malting, sorghum synthesizes the amylases and proteases necessary for brewing. Proteomics revealed that mashing with sorghum malt required higher temperatures than barley malt for efficient protein solubilization. Both α- and β-amylase were considerably less abundant in sorghum wort than in barley wort, correlating with lower maltose concentrations in sorghum wort. However, metabolomics revealed higher glucose concentrations in sorghum wort than in barley wort, consistent with the presence of an abundant α-glucosidase detected by proteomics in sorghum malt. Our results indicate that sorghum can be a viable grain for industrial fermented beverage production, but that its use requires careful process optimization for efficient production of fermentable wort and high-quality beer.

Quantitative analysis of key components in Qingke beer brewing process by multispectral analysis combined with chemometrics

In order to monitor the Qingke beer brewing process in real time, this paper presents an analytical method for predicting the content of key components in the wort during the mashing and boiling stages using multi-spectroscopy combined with chemometrics. The results showed that the Neural Networks (NN) model based on Raman spectroscopy (RPD = 3.9727) and the NN model based on NIR spectroscopy (RPD = 5.1952) had the best prediction performance for the reducing sugar content in the mashing and boiling stages; The partial least Squares (PLS) model based on Raman spectroscopy (RPD = 2.7301) and the NN model based on Raman spectroscopy (RPD = 4.3892) predicted the content of free amino nitrogen best; The PLS model based on UV–Vis spectroscopy (RPD = 4.0412) and the NN model based on Raman spectroscopy (RPD = 4.0540) are most suitable for the quantitative analysis of total phenols. The results can be used as a guide for real-time control of wort quality in industrial production.

Potential of germinated brown rice in beer brewing

Brewing beer with cereals other than barley malt has drawn wide attention in recent years. Germinated brown rice (GBR), which contains high contents of γ-aminobutyric acid (GABA), is a well-known functional food and is widely incorporated as an ingredient in different products. However, little is known about the influence of GBR addition on the processability and quality of beer. The present study aimed to investigate the influence of different contents (0, 20, 40, and 60%) of GBR in the recipe on the beer quality. GBR beers had a lower color (7.60–15.86 EBC), alcohol content (3.02–3.67 %vol), fermentation degree (51.57–59.71%), and bitterness (11.07–14.80 IBU) than Pilsen malt (PM) beer. An enrichment was observed in GABA, which is considered a bioactive component with multiple physiological functions, in all GBR beers prepared and a maximum GABA content of 86.21 mg/L was obtained in 60% GBR beer. Volatile compounds were also analysed and the introduction of GBR led to elevated levels of higher alcohols. Beer with 20% GBR achieved the best sensory characteristics. This study evaluated the brewing potential of GBR in the brewing industry.

The quest for the perfect loaf of sourdough bread continues: Novel developments for selection of sourdough starter cultures

Sourdough fermentation, one of the oldest unit operations in food production, is currently experiencing a revival in bread production at the household, artisanal, and the industrial level. The expanding use of sourdough fermentation in bread production and the adaptation of fermentation to large scale industrial bread production also necessitate the development of novel starter cultures. Developments in the last years also have expanded the tools that are used to assess the metabolic potential of specific strains, species or genera of the Lactobacillaceae and have identified multiple ecological and metabolic traits as clade-specific. This review aims to provide an overview on the clade-specific metabolic potential of members of the Lactobacillaceae for use in sourdough baking, and the impact of these clade-specific traits on bread quality. Emphasis is placed on carbohydrate metabolism, including the conversion of sucrose and starch to soluble polysaccharides, conversion of amino acids, and the metabolism of organic acids. The current state of knowledge to compose multi-strain starter cultures (synthetic microbial communities) that are suitable for back-slopping will also be discussed. Taken together, the communication outlines the current tools for selection of microbes for use in sourdough baking.

MaNAC19–MaXB3 regulatory module mediates sucrose synthesis in banana fruit during ripening

Sucrose, a predominant sweetener in banana (Musa acuminata) fruit, determines sweetness and consumer preferences. Although sucrose phosphate synthase (SPS) is known to catalyze starch conversion into sucrose in banana fruit during the ripening process, the SPS regulatory mechanism during ripening still demands investigation. Hence, this study discovered that the MaSPS1 expression was promoted during ethylene-mediated ripening in banana fruit. MaNAC19, recognized as the MaSPS1 putative binding protein using yeast one-hybrid screening, directly binds to the MaSPS1 promoter, thereby transcriptionally activating its expression, which was verified by transient overexpression experiments, where the sucrose synthesis was accelerated through MaNAC19-induced transcription of MaSPS1. Interestingly, MaXB3, an ethylene-inhibited E3 ligase, was found to ubiquitinate MaNAC19, making it prone to proteasomal degradation, inhibiting transactivation of MaNAC19 to MaSPS1, thereby attenuating MaNAC19-promoted sucrose accumulation. This study's findings collectively illustrated the mechanistic basis of a MaXB3-MaNAC19-MaSPS1 regulatory module controlling sucrose synthesis during banana fruit ripening. These outcomes have broadened our understanding of the regulation mechanisms that contributed to sucrose metabolism occurring in transcriptional and post-transcriptional stages, which might help develop molecular approaches for controlling ripening and improving fruit quality.

Antimelanogenic potential of brewer's spent grain extract through modulation of the MAPK/MITF axis

Beer brewing produces >39 million tons of brewer's spent grain (BSG) per year worldwide. Although BSG is rich in protein, fiber, and phytochemicals, it is mainly used as livestock feed, and some is discarded. In this study, we attempted to assess the antimelanogenesis effects of BSG and identify the functional components. To this end, we investigated the antioxidant and antimelanin synthesis effects of a BSG extract (BSGE). The results showed that BSGE has high DPPH radical-scavenging activity and inhibited α-MSH-induced melanin synthesis in B16F10 cells cultured in both 2D and 3D environments. BSGE also reduced the expression levels of MITF, TRP-1, TRP-2, and tyrosinase in B16F10 cells by regulating the MAPK pathway. We confirmed the skin-whitening effect of BSGE in 3D reconstituted human skin and zebrafish embryo models. HPLC analysis showed that BSGE contains ferulic acid and p-coumaric acid, which are known to have whitening effects. Thus, BSGE can be used in multifunctional cosmetics as a sustainable ingredient with antioxidant and skin-whitening properties.

Simplified Method for Measurement of Arabinoxylan Content in Wort and Beer

Arabinoxylan is a major polysaccharide found in barley and wheat. As this polysaccharide has been reported to be involved in wort viscosity and filterability, as well as β-glucan, it has become increasingly important in beer brewing in recent years, despite the limited availability of a measurement methodology for arabinoxylan. In this study, we developed a simple method for determining arabinoxylan content in wort and beer products using a commercially available xylose determination kit. The results show a relationship between arabinoxylan and the viscosity of wort and beer products. These results were consistent with previous reports, suggesting that this simple method can be used to observe the behavior of arabinoxylan during malting and brewing.

Additional glucoamylase genes increase ethanol productivity on rice and potato waste streams by a recombinant amylolytic yeast

The implementation of consolidated bioprocessing for converting starch to ethanol relies on a robust yeast that produces enough amylases for rapid starch hydrolysis. Furthermore, using low-cost substrates will assist with competitive ethanol prices and support a bioeconomy, especially in developing countries. This paper addresses both challenges with the expression of additional glucoamylase gene copies in an efficient amylolytic strain (Saccharomyces cerevisiae ER T12) derived from the industrial yeast, Ethanol Red™. Recombinant ER T12 was used as a host to increase ethanol productivity during raw starch fermentation; the ER T12.7 variant, selected from various transformants, displayed enhanced raw starch conversion and a 36% higher ethanol concentration than the parental strain after 120 h. Unripe rice, rice bran, potato waste and potato peels were evaluated as alternative starchy substrates to test ER T12.7′s fermenting ability. ER T12.7 produced high ethanol yields at significantly improved ethanol productivity, key criteria for its industrial application.

Comparative Analysis of the Essential Oil Contents of Azadrichta indica and Humulus lulpulus: Could Azadrichta indica Substitute Humulus lulpulus in Beer Brewing?

Hops (Humulus lulpulus) give beer its brewing qualities (iso-alpha acid and essential oil). Hop acid is responsible for bitterness while hop essential oil is responsible for aroma and palate fullness. The aim of the study is to investigate the potentiality of substituting hop oil with neem (Azadrichta indica) oil in beer brewing. The oils were analyzed using Fourier-Transform Infrared (FTIR) spectroscopic technique after extracting the oil by solvent extraction. Hydrocarbon and Sulphur contents were also investigated using their standard methods. FTIR results show that both oils contain similar functional groups. It was observed that some hydrocarbons (myrcene, ocimene and α and β-pinene) present in essential oil of hop were also present in neem leaf oil. Volatile sulphur compounds such as dimethyl sulphide, dimethyl disulphide and dimethyl trisulphide present in hop oil were also found in neem oil. This study revealed that neem oil could be used as a substitute for hop oil in aroma enhancement in beer.

Study on Fermentation Technology and Flavor Substances of Strong Ale Beer

In this study, we selected three kinds of strong ale beer yeast, which were SafAle HA-18, Lallemand Saison and SafAle BE-134, for comparative brewing experiments. The comprehensive sensory evaluations were made by testing the physical and chemical indicators, flavor substances and antioxidant capacities, according to which a yeast suitable for the brewing of ale beer with high alcohol content was selected. We showed that there were some differences between the three kinds of yeast on fermentation performance. HA-18 performed the best on sugar lowering speed, yeast sedimentation, tolerance to alcohol and production of alcohol. Saison was outstanding on reproductive capacity and reduction speed of diacetyl. Although the fermentation speed was relatively close to HA-18, the sedimentation of Saison was poor. BE-134 had better yeast sedimentation, but the overall fermentation performance was average and the sensory quality of the finished beer was poor.

Identification and Characterization of Novel Malto-Oligosaccharide-Forming Amylase AmyCf from Cystobacter sp. Strain CF23.

Malto-oligosaccharides (MOSs) from starch conversion is advantageous for food and pharmaceutical applications. In this study, an efficient malto-oligosaccharide-forming α-amylase AmyCf was identified from myxobacter Cystobacter sp. strain CF23. AmyCf is composed of 417 amino acids with N-terminal 41 amino acids as the signal peptide, and conserved glycoside hydrolase family 13 (GH13) catalytic module and predicted C-terminal domain with β-sheet structure are also identified. Phylogenetic and functional analysis demonstrated that AmyCf is a novel member of GH13_6 subfamily. The special activity of AmyCf toward soluble starch and raw wheat starch is 9249 U/mg and 11 U/mg, respectively. AmyCf has broad substrate specificity toward different types of starches without requiring Ca2+. Under ideal circumstances of 60 °C and pH 7.0, AmyCf hydrolyzes gelatinized starch into maltose and maltotriose and maltotetraose as the main hydrolytic products with more than 80% purity, while maltose and maltotriose are mainly produced from the hydrolysis of raw wheat starch with more than 95% purity. The potential applicability of AmyCf in starch processing is highlighted by its capacity to convert gelatinized starch and raw starch granules into MOSs. This enzymatic conversion technique shows promise for the low-temperature enzymatic conversion of raw starch.

Evidence for metabolite composition underlying consumer preference in Sub-Saharan African Musa spp.

Breeding programs for disease resistant bananas in Sub-Saharan Africa generated resistant bananas, which did not meet fruit quality characteristics preferred by consumers. The present study aimed to establish chemotypes underlying preferred cooking bananas of Matooke, Mchare and plantain and less preferred Mbidde bananas, used for beer brewing. The metabolite data of Mbidde showed higher levels of metabolites associated with sour, sweet, and astringent taste; as well as different textural properties associated with cell wall composition and lignin content. Significant differences in the majority of specialised and primary metabolites were observed in the pulp of cooking banana groups. Analysis of peel tissue indicated similar metabolic differences in the protective layer surrounding the pulp and suggested a distinct genetic regulation of phenylpropanoid and flavonoid pathways between the genome groups. In summary, the present data can be used to establish metabolic traits associated with consumer preference, which can augment modern breeding programs.

Metabolic pathways modulated by coumarin to inhibit seed germination and early seedling growth in Eleusine indica

Coumarin is an allelochemical that is widely present in the plant kingdom and has great potential for weed control. However, its mechanisms of action remain largely unknown. This study employed metabolomic and transcriptomic analyses along with evaluations of amino acid profiles and related physiological indicators to investigate how coumarin inhibits the germination and seedling growth of Eleusine indica by modifying metabolic pathways. At 72 h of germination at 50 and 100 mg L−1 coumarin, E. indica had lower levels of soluble sugar and activities of amylases and higher levels of starch, O2−, H2O2, auxin (IAA) and abscisic acid (ABA) compared to the control. Metabolomic analysis demonstrated that coumarin treatments had a significant impact on the pathways associated with amino acid metabolism and transport and aminoacyl-tRNA biosynthesis. Exposure to coumarin induced significant alterations in the levels of 19 amino acids, with a decrease in 15 of them, including Met, Leu and γ-aminobutyric acid (GABA). Additionally, transcriptomic analysis showed that coumarin significantly disrupted several essential biological processes, including protein translation, secondary metabolite synthesis, and hormone signal transduction. The decrease in TCA cycle metabolite (cis-aconitate, 2-oxoglutarate, and malate) contents was associated with the suppression of transcription for related enzymes. Our findings indicate that the inhibition of germination and growth in E. indica by coumarin involves the suppression of starch conversion to sugars, modification of the amino acid profile, interference of hormone signalling and the induction of oxidative stress. The TCA cycle appears to be one of the most essential pathways affected by coumarin.

Bjarne Kreitz.

"Computational chemistry is fun because 'You get all the fun of sitting still, being quiet, writing down numbers, paying attention,' (quoting The Simpsons since it fits perfectly) … To improve my work-life balance, I started baking sourdough bread and brewing beer." Find out more about Bjarne Kreitz in his Introducing … Profile.

Bio cellulose-based edible composite coating for shelf-life extension of tomatoes

There is an imperious role of coatings for enhancing the shelf-life of vegetables and fruits and can minimize postharvest loss. This study evaluated the impact of coating formulated from bacterial cellulose, starch, sodium alginate, and chitosan on tomatoes. The tomatoes were divided into eight groups and coated with the dipping technique. Non-coated and differently treated tomatoes were assessed under two different temperature conditions, i.e., room temperature (25 ± 2 ͦC) and refrigeration temperature (5 ± 2 ͦC). The efficiency of coatings on various quality parameters was evaluated at different time intervals, such as the 0th, 3rd, 5th, 8th, and 10th days of storage. Storage study of coated tomato samples demonstrated enhancement in firmness and sensory attributes. In addition, the titrable acidity, ascorbic acid content, total plate count, total soluble solids, and loss in weight showed better retention in coated samples than in non-coated (control) samples. The current study showed that all the coating formulations could increase the shelf-life and preserve the quality parameters of tomatoes. The coating made from bacterial cellulose (15 gm/100 mL), starch (3 gm/100 mL), and chitosan (2 gm/100 mL) at refrigeration temperature were found to be the best combination among all the coating as this coating formulation maintained highest quality parameters. This happened because of the maximum inhibition of respiration and minimum conversion of starch into sugar. Thus, coating the tomatoes with these formulations was found to be adequate for application because of its edibility, biodegradability, and non-reactive nature.